1. Field of the Invention
This disclosure relates to a fuel supply device and a fuel supply method for an internal combustion engine that is provided with a high-pressure fuel pump which pressurizes a fuel pumped from a fuel tank and supplies the fuel to a fuel injection valve.
2. Description of Related Art
A high-pressure fuel pump is disposed in an internal combustion engine such as an in-cylinder injection-type internal combustion engine. The high-pressure fuel pump pressurizes a fuel pumped from a fuel tank and supplies the fuel to a fuel injection valve. An electromagnetic valve is disposed in the high-pressure fuel pump. The amount of the fuel that is discharged from the high-pressure fuel pump is adjusted by opening and closing of the electromagnetic valve being controlled.
While the high-pressure fuel pump is in operation, an operation sound is generated as a result of the opening and closing of the electromagnetic valve. During a low-load operation when an overall sound that is generated by the internal combustion engine is not loud, the operation sound of the electromagnetic valve may stand out. Japanese Patent Application Publication No. 2002-213326 discloses a fuel supply device for an internal combustion engine that performs an operation sound suppression control for suppressing an operation frequency of the electromagnetic valves of the high-pressure fuel pumps as a whole, that is, suppressing the electromagnetic valve operation sound by increasing the fuel discharge amount for each opening and closing of the electromagnetic valve of one of the two high-pressure fuel pumps and then stopping a pressurizing operation of the other during a low-load operation with a small required fuel amount.